1. Technical Field
This invention relates to an apparatus for protecting and dispensing items such as medication in solid, powder or liquid form, and more particularly, to an apparatus which can be used by a person to safely carry such items while protecting the items from damage or exposure and allowing the person to immediately and easily access those items.
2. Related Art
xe2x80x9cBlister packsxe2x80x9d or xe2x80x9csoft packsxe2x80x9d are sometimes used to carry items, such as specific dosage medication in pill or powder form, in readily accessible, individually sealed and sterile compartments. Individual compartments making up the blister pack may be opened exclusively of any other compartments in the pack. Typically, these compartments are opened by pushing the contents of the compartment through a frangible membrane sealing the compartment, or by peeling back a covering forming part of the compartment.
The frangible membrane used to seal the individual compartments of blister packs must be made weak enough that the contents of the compartment may be forced through the frangible wall or membrane without being damaged. However, the unfortunate result of this construction is that weak membranes are subject to tearing or rupturing. For example, if a blister pack is carried in a user""s pocket along with a set of keys or other hard items, it is not uncommon for damage to the membranes sealing one or more compartments to occur. Damage to a compartment typically exposes the contents of that compartment to environmental conditions such as moisture or contamination that can render the contents unusable.
The frangible membrane used to seal a compartment may be made strong enough to minimize the possibility of inadvertent tearing or rupturing. However, while increased strength may appear desirable, the usefulness of such a configuration is limited in that forcing the contents of the compartment through the membrane can become increasingly difficult as the strength of the membrane is increased. Further, the structural integrity of the contents of the compartment must be considered when increasing the strength of the membrane. For example, nitroglycerin pills, often carried by a person suffering from angina pectoris, are very soft, having a consistency similar to compacted powdered sugar. Attempting to force such pills through even a very weak membrane will tend to pulverize the pills, with the result that the medication is difficult or impossible to ingest.
Further, it is often desirable to place liquids or powders within a compartment of a blister pack. It is difficult to force such compositions through a frangible membrane. Making a membrane weak enough to allow its use with liquids or powders creates a configuration that is extremely susceptible to damage by tearing and/or rupturing.
Blister pack configurations having coverings that may be peeled back to expose the contents of a compartment in the pack also have problems. For example, it is not uncommon for an area of the covering to tear away in such a manner as to expose more than one compartment. Where it is not desired to open or expose more than one compartment at a time, the contents of any additional fully or partially opened compartments may be exposed to moisture or other contaminants that render those contents unusable.
Further, a common problem associated with peelable coverings is that such coverings tend to give way suddenly as the surface area to which they are attached decreases while they are being peeled back. In such cases, the contents of the compartment enclosed by the cover may be flung out of the compartment as the cover suddenly gives way. This may result in damage or contamination of the contents, thereby rendering the contents unusable. In addition, such configurations are not suitable for use in containing liquids or powders, as the possibility of spillage is dramatically increased.
Various solutions have been devised in an attempt to address some of the problems described above. For example, some blister packs have sharp external prongs designed to pierce a cover or seal, then to pierce the skin against which such blister packs are pressed. These blister packs have been designed to deliver intracutaneous injections of liquid medication that coats the prongs. Such configurations are not capable of delivering powdered or solid medications or other items.
Other designs use cumbersome or complicated external cutter devices designed to cut the covering of a compartment in a blister pack. For example, some blister packs have external cutters that must be pressed through a frangible covering, rotated to cut or tear the covering, then pulled back or removed to expose the contents of the compartment. Such devices can be complicated and expensive to manufacture. Further, such devices may be difficult to operate, especially where they are designed to provide xe2x80x9cchild resistance,xe2x80x9d and/or where the user has trembling or unsteady hands, or is otherwise impaired.
Still other blister pack designs use sharpened prongs within the compartments of the pack to pierce a frangible covering to allow mixing of a binary compound contained within sub-compartments. However, simply piercing the covering in one or more places does not provide an adequate opening to allow the contents of a compartment to be quickly and completely evacuated or removed from the compartment. Often, especially with powders and liquids, a portion of the contents remains in the compartment and is lost because the prongs do not create a sufficient path for complete egress of the contents. Consequently, use of such designs requires either increasing the volume of the liquid or powder to account for the loss, or simply ignoring the issue altogether.
Still other solutions, such as requiring the blister pack to be placed within separate mechanisms having cutters designed to open one or more compartments, have been suggested. Such devices tend to be relatively expensive and complicated, especially where they must also function as a medication dispenser for liquid and/or powder medications.
Accordingly, there is a need for a blister pack that overcomes the problems associated with current blister pack designs. This blister pack would be sealed with a membrane or covering of sufficient strength to prevent inadvertent tearing or rupturing. To ensure that the contents of a compartment are protected during removal, the blister pack would not require that the contents of the compartment be forced through the membrane or covering in order to open the compartment, or that the covering be manually peeled back to expose the contents of the compartment. Further, the blister pack would work equally well with solids, powders, soft or semi-solid items, or liquids without requiring external cutters or opening devices. In addition, the blister pack would provide an open path for complete evacuation of liquids and powders. The blister pack would be extremely easy to operate, even where the user was in an impaired state, or had unsteady or shaking hands. Finally, the blister pack would be simple and inexpensive to manufacture.
To overcome the limitations in the related art described above, and to overcome other limitations that will become apparent upon reading and understanding the present application, the present invention is embodied in an apparatus, such as a blister pack, having the capability to safely store and protect items such as medication in solid, soft or semi-solid, powder, or liquid form, while allowing such items to be easily and rapidly dispensed by a user.
In general, the present invention is preferably embodied in a xe2x80x9cpill packxe2x80x9d or xe2x80x9cblister packxe2x80x9d having a flexible plastic upper membrane including at least one depressing dome. A lower membrane serves to seal items such as pills, powders, or liquids between the pill pack""s upper and lower membranes. An annular-shaped internal punch or cutter resides within the depressing dome between the upper and lower membranes, oriented perpendicular to the membranes. Pills, powders, liquids or other items are sealed within the void or chamber created by the structure of the annular punch or cutter and the upper and lower membranes of the pill pack. One or more such chambers may be arranged in rows and/or columns to provide the desired amount of storage.
The lower membrane is of sufficient strength to prevent inadvertent tearing or rupturing of the membrane, even when carried in a relatively hostile environment, such as with metal keys in a users pocket. However, the internal cutter is capable of cutting through this membrane by simply depressing the dome thereby providing an open path for rapid and complete evacuation of the chamber contents.
In operation, a user preferably depresses the depressing dome which forces the annular cutter through the lower membrane, thereby opening the lower membrane and allowing the release of the contents of the chamber to the user. Unlike more complicated devices which require manipulation of external cutter devices, or carefully peeling back a membrane, a user having unsteady or shaking hands would be able to depress the dome to open the chamber thereby releasing the contents.
Further, because the volume of the chamber decreases as the dome is depressed, the internal pressure within the chamber is preferably increased prior to cutting the lower membrane. The increased pressure preferably serves to propel the contents out of the chamber as the lower membrane is cut. This feature is especially useful in dispensing powders and liquids.
For example, in one embodiment, the pill pack may be used with a medication carrier/inhaler for powdered medication. As the dome is depressed, the cutter cuts the lower membrane, and the increased pressure within the chamber propels the powder within the chamber into the inhaler where a user immediately inhales the powdered medication.
In addition, because there are no moving parts, simply an upper membrane having a flexible plastic dome with an internal cutter, the upper membrane may be inexpensively and easily fabricated by methods such as injection molding using a thermoplastic compound. The lower membrane may also be inexpensively and easily fabricated from any suitable material such as, for example, metal foil or plastic. The upper and lower membranes are preferably bonded together, using conventional techniques, to hermetically seal the contents of at least one chamber.
The foregoing and still further features and advantages of the present invention as well as a more complete understanding thereof will be made apparent from a study of the following detailed description of the invention in connection with the accompanying drawings and appended claims.